[OANNES Foro] Seasonal variability of gillnet selectivity in Chilean hake Merluccius gayi gayi

[Mario Cabrejos]

·         Journal of Applied Ichthyology 

·         First published: 10 April 2017 

·         DOI: 10.1111/jai.13336   


 


Seasonal variability of gillnet selectivity in Chilean hake Merluccius gayi
gayi (Guichenot, 1848)


·         D. Queirolo, A. Flores


0.      


Summary


This study examines the seasonal variability in gillnet size selectivity for
the main Chilean hake (Merluccius gayi gayi) fishery off the coast of
central Chile. Selectivity estimates were based on five gillnet mesh sizes
(50, 60, 70, 80, 90 mm) in four traditional fishing areas, and during
periods of low and high reproductive activity. Average fish length caught in
the earlier period (low reproductive activity) was 30.8 cm LT (±4.17), and
significantly longer (p < .05) at 35.9 cm TL (±6.15) in the latter period
(high reproductive activity). For males, the selectivity factor was similar
in both periods, thus the estimated modal lengths did not differ seasonally
(p > .05). For females, however, both the selectivity factor and the
estimated modal lengths changed significantly depending on the time of year
(p < .05). A significant increment was estimated in the girth/perimeter
ratio and condition factor during the period of higher reproductive
activity. This change in the fish girth of females during spawning helps
explain the significant reduction in their selectivity factor estimates in
August–October.

 



---
This email is free from viruses and malware because avast! Antivirus protection is active.
https://www.avast.com/antivirus
------------ próxima parte ------------
Se ha borrado un adjunto en formato HTML...
URL: <http://lista.oannes.org.pe/pipermail/oannes-oannes.org.pe/attachments/20170412/c1c2e208/attachment.html>